All disc drives today require two precision moving parts and two motors, one for driving the actuator to position the transducer relative to the rotating disc, and a second motor to rotate the disc at a constant speed. Associated control circuitry is required for each of the motors. Substantial cost reduction is possible if a drive could be built with only one moving part or assembly. Theoretically, the cost of the mechanism and control electronics could be reduced as much as 50 percent.
All current hard disc drives have one or more rotating discs mounted on a precision spindle motor which runs at a constant speed. The data on the surface of the disc is stored in circular, concentric tracks, and is accessed using a transducer mounted on an actuator arm. The actuator arm is controlled in either linear or rotary fashion to access any location on the concentric tracks.
The actuator is controlled to maintain the transducer over the desired track location by open or closed loop servo techniques.
Typically, the transducer head is parked on power down in a landing zone, or unloaded off the disc.
The objective in the present invention is to eliminate the need for separate motors for the spindle rotation and actuator positioning, thereby reducing the parts count and the basic material costs in the disc drive.